Jyothirmai M V, Saini Himanshu, Park Noejung, Thapa Ranjit
SRM Research Institute & Department of Physics and Nanotechnology, SRM Institute of Science and Technology, Kattankulathur, 603203, Tamil Nadu, India.
Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 689-798, South Korea.
Sci Rep. 2019 Nov 5;9(1):15983. doi: 10.1038/s41598-019-52410-3.
The earth abundant and non-toxic solar absorber material kesterite CuZnSn(S/Se) has been studied to achieve high power conversion efficiency beyond various limitations, such as secondary phases, antisite defects, band gap adjustment and microstructure. To alleviate these hurdles, we employed screening based approach to find suitable cationic dopant that can promote the current density and the theoretical maximum upper limit of the energy conversion efficiency (P(%)) of CZTS/Se solar devices. For this task, the hybrid functional (Heyd, Scuseria and Ernzerhof, HSE06) were used to study the electronic and optical properties of cation (Al, Sb, Ga, Ba) doped CZTS/Se. Our in-depth investigation reveals that the Sb atom is suitable dopant of CZTS/CZTSe and also it has comparable bulk modulus as of pure material. The optical absorption coefficient of Sb doped CZTS/Se is considerably larger than the pure materials because of easy formation of visible range exciton due to the presence of defect state below the Fermi level, which leads to an increase in the current density and P(%). Our results demonstrate that the lower formation energy, preferable energy gap and excellent optical absorption of the Sb doped CZTS/Se make it potential component for relatively high efficient solar cells.
地球上储量丰富且无毒的太阳能吸收材料硫铜锡锌矿CuZnSn(S/Se)已被研究，以突破各种限制，实现高功率转换效率，这些限制包括次生相、反位缺陷、带隙调整和微观结构等。为了克服这些障碍，我们采用基于筛选的方法来寻找合适的阳离子掺杂剂，该掺杂剂可以提高CZTS/Se太阳能器件的电流密度和能量转换效率（P(%)）的理论最大上限。对于这项任务，使用杂化泛函（Heyd、Scuseria和Ernzerhof，HSE06）来研究阳离子（Al、Sb、Ga、Ba）掺杂的CZTS/Se的电子和光学性质。我们的深入研究表明，Sb原子是CZTS/CZTSe合适的掺杂剂，并且它与纯材料具有相当的体模量。由于费米能级以下存在缺陷态，易于形成可见光范围的激子，Sb掺杂的CZTS/Se的光吸收系数比纯材料大得多，这导致电流密度和P(%)增加。我们的结果表明，Sb掺杂的CZTS/Se较低的形成能、合适的能隙和优异的光吸收使其成为相对高效太阳能电池的潜在组件。
